The purpose of this Inter-Agency Agreement is to investigate the importance of gut microbiota in providing isothiocyanates from cooked broccoli, a popular Brassica vegetable. As the appreciation for the importance of gut microbiota increases, new questions emerge regarding whether gut microbiota can replace the need for dietary myrosinase (which is destroyed in cooking) to be consumed with cooked Brassica vegetables. This Inter-Agency Agreement will provide the means to conduct a human feeding study to investigate the extent of microbial conversion of glucosinolates to isothiocyanates with and without repeated Brassica intake. The focus will be broccoli initially, since broccoli is a particularly well-consumed Brassica vegetable. This study will have added value as an extension of a previous collaborative broccoli adaptation study in which a dietary source of myrosinase was provided with the cooked broccoli. For this study, no dietary myrosinase will be provided, thus isolating the gut microbial conversion of glucosinolate glucoraphanin to isothiocyanate sulphoraphane. Blood and urine will be analyzed for isothiocyanates. Fecal samples will be analyzed for microbiota composition.